Mobile Broadband (MBB) based on High Speed Packet Access/Long Term Evolution (HSPA/LTE) and other mobile communication standards has taken off as an important technology for connecting User Equipments (UEs) like e.g. mobile Personal Computers (PCs) to the Internet. As Mobile Broadband (MBB) takes off new types of equipment appears on the market such as Fixed Wireless Access (FWA) solutions. In addition, the usage of broadband wireless adaptors so called “dongles” and built-in MBB capabilities for PCs and laptops is increasing heavily. A dongle is a small piece of hardware that connects to a laptop or desktop computer. A dongle refers to a broadband wireless adaptor or in general to connectors that translate one type of port to another.
FWA is about providing end users such as UEs or PCs with fixed line services by utilizing a wireless technology, e.g. Universal Mobile Telecommunications System (UMTS), Global System for Mobile communications (GSM), Wideband Code Division Multiple Access (WCDMA), System Architecture Evolution/Long Term Evolution (SAE/LTE), Code Division Multiple Access (CDMA) or Worldwide Interoperability for Microwave Access (WiMAX) technologies. Most FWA solutions comprise specific Fixed Wireless Terminals (FWTs), also known as Mobile Broadband Routers (MBR). The FWTs offer a cost efficient way to provide high speed data, voice and fax services to small/home office and residential users.
A FWT is a box that from the end user perspective may be compared for example with an Asymmetric Digital Subscriber Line (ADSL) modem, and form a base station perspective the FWTs are seen as UEs. The FWT may also contain router functionality, Ethernet switch and WLAN functionality in order to give connectivity to several devices. However, the FWT normally uses a mobile network i.e. the wireless communications network, for backhaul and Internet connectivity instead of the fixed broadband. In a hierarchical wireless communications network backhaul links are links of the wireless communications network which comprise intermediate links between the Mobile Core Network (mobile CN), normally via a macro Base Station (macro BS), and home Base Stations (home BSs) at the “edge” of the entire hierarchical network, i.e. typically wired connections.
FIG. 1 depicts main principle of how FWA and FWT implementation may appear. The FWT device 1 here is for example located in an end user's home 2, normally in a same location all the time i.e. there is no real mobility related to the FWT except “nomadicity”, i.e. that the FWT could be powered off in one place, moved to another location and then powered on again. The FWT 1 normally provides local connectivity and services for end user equipments located in the home 2 using for example WLAN/WiFi 3 or Ethernet 4 as the media for communication. Examples of end user equipments may for example be a printer 5, a PC 6 or a cable TV box 7. In addition, the FWT may provide support for connectivity for multiple legacy services, for example a fixed phone 8 or a fax 9. The FWT may then directly be connected to mobile RAN 10 and further on to a mobile CN 11 and by which the FWT may for example provide access towards the Internet 12. A dongle 13 attached to the PC 6 may similarly provide connectivity to the Internet 12 for the PC 6 by using the wireless communications network 100, via the RAN 10 directly. Additionally, a Network Attached Storage (NAS) 14 may also be connected to the FWT1 via said WLAN/WiFi 3 connection. Normally, the NAS 14 includes different material like movies, music, pictures that other devices i.e. end-user devices such as the PC 6, may access.
To the wireless communications network 100, these devices, stationary UEs e.g. FWT 1 and PCs 6 with dongles 13 appear as normal User Equipments (UEs), even though they are more or less stationary and do not require a high degree of mobility, compared to UEs (mobile phones) in general, which the wireless communications network is generally designed for. Due to the increased number of FWTs and PCs connecting with dongles to the RAN 10 directly or via a FWT, on the market data traffic generated by these equipments is increasing substantially causing a heavy load on the mobile CN.
FIG. 2a depicts another view of general prior art wireless communications network 100 that, according to this example, uses SAE/LTE technology to provide backhaul connection for UEs and wherein the architecture illustrates a non-roaming architecture for 3GPP accesses. However other technologies may similarly be presented here such as e.g. WCDMA, GSM/Enhanced Data Rates for GSM Evolution (EDGE) or WiMAX.
The wireless communications network 100 using SAE/LTE technology comprises a User Equipment (UE) 101, an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) 107, a Mobility Management Entity (MME) 103, a Serving Gateway (S-GW) 104, Packet Data Network Gateway (PDN GW) 105 and a Home subscriber server (HSS) 106. Even though the S-GW 104 and the PDN GW 105 are indicated as separate entities, they may be combined in a single entity, not shown in FIG. 2a. The wireless communications network normally comprises several S-GW 104/PDN GW 105 nodes which are considered to be global gateway nodes.
Continuing with the description of FIG. 2a, the E-UTRAN 107 is a radio access network that interfaces both to the UE 101 and the core network nodes. The E-UTRAN 107 may comprise an eNB 102, also called eNodeB, with a transmitter and a receiver for communicating with the UE 101. Alternatively, the eNodeB 102 may also comprise a local Gateway (local GW) 1020 which may provide access towards the Internet (/Intranet). The local GW 1020 may also be located separately nearby the eNodeB 102. The Local GW 1020 may also comprise total 5-GW/PDN GW functionality, or just a subset of the functionality. Many such local GWs may exist in parallel in the wireless communications network 100.
The MME 103 is a key control-node for the LTE radio access network. It is involved in the bearer activation/deactivation process and is also responsible for choosing the S-GW 104 for the UE 101 at initial attach and at time of intra-LTE handover involving Core Network (CN) node relocation. The MME 103 may further be in connection with a Serving GPRS Support Node (SGSN) 109 which is a main component of GSM/GPRS and UTRAN/WCDMA packet domain networks, and which handles all packet switched data oriented functions within the network, e.g. mobility management and authentication of the UEs. Note that the SGSN 109 may further be in near connection with the MSC i.e. logically separate nodes but still physically integrated.
The S-GW 104 routes and forwards user data packets, while also acting as the mobility anchor for the user plane during inter-eNB handovers and as an anchor for mobility between LTE and other 3GPP technologies. The user plane is functions that deal with issues of user-to-user information transfer and associated controls. The S-GW 104 manages and stores UE 101 contexts, e.g. parameters of the IP bearer service and network internal routing information.
The PDN GW 105 provides connectivity to the user equipment 101 to external packet data networks and IP services 108 provided by different operators by being the point of exit and entry of traffic for the UE 101. A UE 101 may have simultaneous connectivity with more than one PDN GW for accessing multiple PDNs. The PDN GW 105 performs policy enforcement, packet filtering for each user, charging support, lawful Interception and packet screening. Another key role of the PDN GW is to act as the anchor for mobility between 3GPP and non-3GPP technologies such as WiMAX and 3GPP2 (CDMA 1× and EvDO). The PDN GW 105 is normally in connection with a Policy Charging and Rules Function (PCRF) node 110 which is the node designated to in real-time determine policy rules in a multimedia network.
The HSS 106 manages the subscriber information and location information of the user equipment 101.
The reference points illustrated in FIG. 2a are: LTE-Uu which is the reference point between the UE and the eNodeB; S1-MME which is the reference point for a control plane protocols between the E-UTRAN 107 and the MME 103; S1-U which is the reference point between the E-UTRAN 107 and the S-GW 104 for a per bearer user plane tunnelling and inter eNodeB path switching during handover; S3 which enables user and bearer information exchange for inter 3GPP access network mobility in idle and/or active state; S4 which provides related control and mobility support between GSM/GPRS Core and WCDMA/UTRAN packet core networks and 3GPP Anchor function of S-GW 104. In addition, if a “Direct Tunnel” is not established, it provides user plane tunnelling; S5 which provides user plane tunnelling and tunnel management between S-GW 104 and PDN GW 105, and is used for S-GW 104 relocation due to UE 101 mobility and if the S-GW 104 needs to connect to a non-collocated PDN GW 105 for a required PDN connectivity; S6a which enables transfer of subscription and authentication data for authenticating/authorizing UE 101 access to an evolved system (AAA interface) between MME 103 and HSS 106. Gx which provides transfer of Quality of Service (QoS) policy and charging rules, from PCRF 110, to a Policy and Charging Enforcement Function (PCEF) in the PDN GW 105; S10 is the reference point between MMES for MME relocation and MME to MME information transfer; S11 is the reference point between the MME 103 and the S-GW 104. S12 is the Reference point between UTRAN and S-GW 104 for user plane tunnelling when “Direct Tunnel” is established. It is based on an Iu-u/Gn-u reference point using GPRS Tunneling Protocol-Users (GTP-U) protocol as defined between the SGSN 109 and the UTRAN or respectively between SGSN 109 and Gateway GSN (GGSN), and wherein usage of the S12 is an operator configuration option; SGi is the reference point between the PDN GW 105 and a packet data network and wherein the packet data network may be an operator external public or private packet data network or an intra operator packet data network 108, e.g. for provision of IMS services. Rx is the Rx reference point that resides between the PCRF 105 and the packet data network 108.
Following from FIG. 2a, now FIG. 2b further shows how a FWT 201 is logically built up and located within the wireless communications network 100 i.e. towards the SAE/LTE network, which in this illustration is the E-UTRAN 107. The FWT 201 according to this illustration comprises a Home Gateway 203 (Home GW) and an UE 202 part that uses the LTE-Uu interface for access and communication with the E-UTRAN 107. Generally, the FWT 201 also comprises a Subscriber Identity Module/Universal Subscriber Identity Module (SIM/USIM) card, as normally would the UE and other terminals connected to the mobile operator's network. The left side of the FWT is shown as a Home GW that provides a “Home” or “Residential LAN” connectivity for the devices in the home, as illustrated in FIG. 1. For example, in FIG. 1, a PC 6 may use WLAN to attach to a Home LAN provided by the Home GW and thereby connectivity to services provided by other devices in the Home LAN.
In LTE/SAE systems, the wireless communications network 100 provides Internet connectivity from the PDN GW 105, as illustrated by FIG. 2a and FIG. 2b. In a 3G (WCDMA) system a corresponding node is called GGSN wherein the GGSN may comprise the functionalities of both a Serving-GW and a PDN GW. Normally only a few of these nodes exists in a wireless communications network 100. Which node a UE should use for communicating is selected when a connection is/has been established. Often, the S-GW and the PDN GW are combined in one node, even though they are illustrated as separate nodes in the figures.
According to prior art, selection of a PDN GW 105 (or S-GW/PDN GW node) is based on data configured for the UE 101 in the HSS 106, or based on predefined so-called Access Point Name (APN) which the UE 101 sends in at a request for establishment of a connection. The APN is then ‘mapped’ to a specific PDN GW. The selection of a S-GW 104 is based on network topology and may further be based on possible preferences to avoid changing S-GW, i.e. the latter to optimize for mobility. In LTE/SAE, these selections are normally performed by the MME 103. It is also very common that the S-GW 104 and PDN-GW 105 are co-located which needs to be taken into account in the PDN GW and S-GW selection.
As described above, a PDN-GW could be selected based on data stored in the HSS 106 for a UE 101 or on data stored in the UE. This is however a very static way normally requiring manual action in order to set and change data in the HSS. For example a lot of operation and maintenance (O&M) is required to handle when subscribers i.e. FWT 1, PC 6 with dongle 13, are moving to other apartments/houses (locations) in the case when information about the PDN-GW to be used would be stored in the HSS.
With the introduction of Local IP Access (LIPA) and Selective IP Traffic Offload (SIPTO) which are features that make it possible to optimize transport of user plane transport for a UE at the expense of mobility support for the UE, and a massive growth of MBB users which most often are stationary in the wireless communications network 100 there is a need to have an efficient selection procedure of a S-GW/PDN GW for these users e.g. FWTs and PCs with dongle.